When I specify
Build-Depends: base, parsec, HaXml >= 1.19.4
in xml-parsec.cabal
it does install correctly.
I guess what happens is that cabal install takes the earliest version
of a package registered to try to build. I guess that's a reasonable
default.
What seems unreasonable to me is that cabal continued to take the
earlier version even after I hid it with ghc-pkg hide.
My advice would be to improve the error message to read
"... Could not find module `Text.XML.HaXml.Posn':
it is a member of package HaXml-1.19.4, which is hidden
It can be unhidden by adding
Build-Depends: HaXml >= 1.19.4
to xml-parsec.cabal"
That leaves the issue of cabal upgrade not upgrading to the latest
version available on hackage, which still feels like a real bug to me.
Best, Thomas.
2008/11/15 Thomas Hartman <tphyahoo at gmail.com>:
> I was upgrading happstutorial.com to ghc 6.10.1 when I came across a
> cabal install issue.
>> Somewhere in day 1 (probably as a HAppS dependency), HaXml 1.13.1 got installed.
>> On day 2, I wanted the latest version of HaXml (1.19.4), a dependency
> for for xml-parsec.
>> cabal install HaXml gave me: already installed.
> cabal upgrade HaXml gave me: some installing action, but in the end I
> wound up with 1.13.1 again.
>> cabal install HaXml-1.19.4 gave me what I want, the latest version.
>> But even then, when I do cabal install xml-parsec I get
>> Text/ParserCombinators/Parsec/XML.hs:18:7:
> Could not find module `Text.XML.HaXml.Posn':
> it is a member of package HaXml-1.19.4, which is hidden
>> The cabal file has
>> Build-Depends: base, parsec, HaXml
>>>ghc-pkg latest HaXml says
> HaXml-1.19.4
>> Even after ghc-pkg hide HaXml-1.13.3
>> I get the same result, so I'm not even sure if the problems I'm having
> are a result of the having two versions of the same package installed.
>> This is a bug right?
>> Any advice on how to get xml-parsec installed?
>> thomas.
>